An ionization chamber for the dosimetry of 14 MeV neutron beams

Abstract

A cylindrical ionization chamber with polythene walls, central electrode, and thin carbon conducting surfaces is described. Its calibration for measuring absorbed dose in a medium irradiated with a fast neutron beam is discussed. The dose to soft tissue is given by D_T=0.79x_c/R_cR_T, where R_c is the reading obtained with the chamber given an exposure x_c roentgens of ⁶⁰Co gamma -rays, and R_T is the reading obtained in the neutron beam. It is estimated that the uncertainty on D_T is +or-6%.